"For every one you see, there might be 10 buried in the ice," Bob Fisher, president of the Illinois Ornithological Society, was quoted in the Chicago Tribune as saying. "When the lake kind of really releases a lot of its ice, you may see a lot of duck remains washing up on shore. But then again, a lot of them may become waterlogged and sink to the bottom, and you never see them."

10 Stunning Lake Michigan Ice Photos

Not only did the birds find it difficult to find food, but the ice surface makes it more difficult for the birds to get the running start on water they need to take flight.

Most of the dead waterfowl that have been recovered have been red-breasted mergansers, said Field Museum research assistant and ornithologist Josh Engel. Many others were white-winged scoters.

A quick thaw with upcoming warming temperatures won't be able to save those who are already seriously malnourished, experts said.